HH,
You weren't there, you didn't see the leak size or location. After an incident like this it would be so easy for a crew succumb to the 'oh **** what have we done' aspect and lose control of the situation. They remained calm and rational and made sensible decisions with the information they had and are to be commended for that.
Out of interest have you ever tried to set fire to Jet A1? It's harder than you think. People get very badly hurt evacuating from a 747, it's not a decision to take lightly.
Lad